Pathophysiology and prognosis of hearing acuity in 16 ears of 10 cases with inner ear syphilis were studied by the transtympanic electrode technique of electrocochleography.
The results were obtained as follows:
The improvement of hearing acuity after steroid therapy was obtained at low frequency range on audiogram. These cases showed a well defined AP, a dominant-SP and remarkable CM response at 0.5kHz. It was speculated that there may be endolymphatic hydrops and the reversible change of hair cells at low frequency area of the cochlea.
On the other hand, in the cases showing slight improvement of hearing acuity, both AP and CM responses shwed a low out-put potential which suggests a reversible change or organic damage of the hair cells or cochlear nevre.
